As far as I can tell, once OKC has decided you like something, there's no way to explicitly tell it you don't. Even removing it from your profile doesn't kick in immediately. If someone searches for, say, "scientology," and you put in your profile that "scientology is crap," you will come up on the search. This is not what either of you is trying to accomplish. Besides, that doesn't describe you. If you're an active organizer of major scientology protests and are looking for someone to do that with you, okay, put it in. Short of that, don't give yourself keywords you don't want.

When I worked on a "search and metrics" team, one of the things we discovered by trying a recommendations engine implementation on a slice of the site's traffic for a bit was that what seemed to matter most for the purposes of the recommendation engine was simply that a user had any reaction at all to a video. It seemed that the vast majority of content space just bores any given person, but "passions predict passions" even when the passions have different valence (hate/love).

Maybe my experiences don't apply here, but it doesn't seem entirely unreasonable to imagine that OKCupid's "stupid algorithm" operating on naive behavior could out perform algorithmically aware meta-strategy that "made sense" but hadn't been validated with some sort of field experimentation :-)